Adobe Lightroom is a deep and powerful piece of software with many techniques available for use. Some of the more well-known tools can be overlooked and one photographer believes that is the Radial filter tool is a prime example.
I admit, I do not do the bulk of my editing in Lightroom. I have used Photoshop for so many years that it is easier and smoother for me to put the heavy lifting of my workflow into it. That said, Lightroom is brilliant for raw processing and there are certain features above and beyond the sliders I still use. One of those is, in fact, the Radial filter.
People use the Radial filter tool for a number of different applications, from adding vignettes to accentuating the light in a landscape. For me, the tool is excellent for helping to guide the viewer's eye. Much of what composition aims to achieve is the attention of viewers for a long as possible, in the correct part of the image. I find that if you use the Radial filter extremely subtly, you can aid in guiding the viewer's eye to the subject you want them to be looking at. By darkening the areas around your subject, or by raising the exposure of your subject, the contrast adds more guidance. As with all things, this needs to be done with a careful hand or you will make the image look unrealistic and jarring.